Power consumption trends in wireless networks

COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED.

Power consumption trends in wireless networksStephen Wilkus, DMTS, Wireless Chief Technology Officee-Energy Conference, June 1, 2011


2

Setting the Stage What? Why worry?

• Historically, Power reduction has been driven by thermal, miniaturization, material cost, and some minor OPEX concerns.

• Recently, regulation, OPEX, Consumer Demands and Social Responsibility are increasingly driving products toward lower power consumption.

• Now, Exploding Wireless Data usage is emerging as the driver for improved efficiency.

• Forecasts of Wireless Data Usage growth by 30 times from 2010 to 2015.

• Operators cannot deploy 30x the base stations or consume 30 times the power.

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3

Cost of Electrical Power for one random site

The marginal price per kWh

paid by a typical operator at a

particular base station is:

3.3¢/kWh delivery charge

11¢/kWh for generation

14.3¢/kWh marginal price

(cost of an additional kWh).

$2546/year Total cost$1880/year

Marginal cost

1152 kWh/32 days = 1.50 kWatt average


4

Typical North American OPEX Costs per Base Station

• Example OPEX Costs/month

Electrical Power: $ 223.05Real Estate Rental: $2,745.83Backhaul (est.): $4,000.00 (10 T1s at $400/mo)

Field Service (est.): $ 500($200K/year loaded salary for 30 BTSs)

Total: $ 7,469/mo$89,626/yr

• In specific situations and specific countries, costs to deliver diesel to remote BTSs or different tariff approaches can lead to very different costs.

Centerville Site monthly rentalOPER 1 Lower 56' $ 833.33 OPER 3 upper pos. $1,700.00 OPER 3b upper $1,800.00 OPER 4 upper $2,458.33 OPER 5 upper $2,416.67

Crawford Corner siteOPER 6 upper 140' $2,745.83

Backhaul

53%

Real

Estate

Lease

37%

Electrical

Power

3%

Field

Service

7%


5

15 000 000

equivalent cars of CO2e

15 000 000

equivalent cars of CO2e

5 000 000 000people without

broadband

5 000 000 000people without

broadband

3+ Modes5+ Bands

3+ Modes5+ Bands

5 000 000towers

5 000 000towers

But with 100% YOY wireless traffic growth,“More of the same” is not enough

More energy, more space, more maintenanceMore energy, more space, more maintenance

That’s 30x in 5 years.


6

Based on: ETSI RRS05_024updated March 2011

Global Energy Consumption of Mobile Network

Components

Assumptions:

Subscriber uses 1 Whr/day

TWh/yr for power mix of 0.507 kg CO2 / kWh

Base Stations consume ~1.7kW average,

(does not include AC, back office or embedded CO2)

Subscribers Base Stations Net. Control Core Network

# 5 Billion 5 Million 17,000 2,500

Power 0.1 W 1.7 kW 1 kW 10 kW

Energy/yr 2 TWh 75 TWh <1 TWh ~1 TWh

Eq. CO2/yr ~1 Mt 38Mt <0.1 Mt <0.5 Mt

GGSN, HLR, AAA, MMEIP CoreePC

GGSN, HLR, AAA, MMEIP CoreePC

RNC

MSC BSC


7

1. Setting the stage

2. Historical background and trends in Base Station Power Consumption

3. Technology Trends for Power Reduction

AGENDA


8

Rectifier

15%

Backhaul

0%

Sig. Proc.

8%

Filter/LNA

2%

AMPS

73%

RF PWR

2%

Power Consumption at Base Station Sites-- Estimated for 1979 --

Only 1.9% of AC power was transmitted into the air

Shelter

Air

Cond.

Not

Incl. Filters/ LNA200? Watts diss.

Amplifiers~9600 Watts

Signal Proc.1000? Watts

Rectifiers

~1900 Watts

Backhaul0 Watts

Base Station

3x80

Watts

RF

Coaxial Feeder

50% loss

3x80 Watts

dissipated

Circa 1979 base station with 3 sectors each generating 16 carriers at 10 Watts out of cabinet. Assumed 5% efficiency.

Air Conditioning was part of the central office, not included here.

Representative values are shown for peak load only.

12700

Watts

AC

480W


9

Air Cond.

16%

Rectifier

8%

Backhaul

2%

Sig. Proc.

10%

Filter/LNA

2%

AMPS

56%

RF PWR

6%

Power Consumption at Base Station SitesTypical in field today

Only 3% of AC power was transmitted into the air

Shelter

Air

Cond.

620

Watts Filters/ LNA3x29 Watts diss.

Amplifiers3x732 Watts diss.

Signal Proc.396 Watts

Rectifiers334 Watts

Backhaul86 Watts

Base Station

3x40

Watts

RF

Coaxial Feeder

50% loss

Early 2000s base station with 3 sectors each generating 5x16 Watts for 5 CDMA carriers. Air Conditioning for the shelter operating part time.

Cables have passive losses of 3dB.

Representative values are shown for OPEX load.

3960

Watts

AC

240W


10

Energy Consumption of Radio Access EquipmentIn the field today with Towertop RRHs

Remote

Radio Heads20% efficiency

3 Antennas

Base Station Rack

1080W

AC Power In

Platform

11% of power is transmitted into the air 3x40W

3x20W

DC and opticalfeeder:no loss

55% to RRH

600W

RF power

120W

AC & Rectifier100W

SignalProcessing

280W

Fans100W

Remote Radio Head, passive cooling and efficiency increased to >20% (available equipment)

480W to rack


11

Energy Consumption of Radio Access EquipmentCurrent products

Remote

Radio Heads40% efficiency

RF Power Amps

3 Antennas

Base Station Rack

600W

AC Power In

Platform

3x40W

3x20W

DC and opticalfeeder:no loss

50% to RRH

300W

RF power

120W

AC & Rectifier40W

SignalProcessing

220W

Fans40W

Remote Radio Heads, passive cooling and high amplifier efficiency

>20% of power is transmitted into the air

300W to rack


12

Study on Energy Efficient Radio Access Network Technologies, 2009Alcatel-Lucent / TU Dresden Vodafone Chair Mobile Communications Systems

Energy Consumption of Radio Access Equipment

Where is the power going?

Energy saving at antenna feed and RF amplifier is most efficient :

Additional savings in power supply and cooling !


13

1. Setting the stage

2. Historical background and trends inBase Station Power Consumption

3. Technology Trends for Power Reduction

AGENDA


14

Power amplifier concept roadmap

March 2011

Class S

Envelope Tracking

Class AB

Doherty

Time

Efficiency

switching and envelope reconstruction

load modulation to keep efficiency high

drain voltage modulation to keep efficiency high

today

Based on linear transistor

operation mode

Transistor operated

as a Switch

increased

flexibility

& sustaina

bility

mid termpast


15

Effect of Power Amplifier Efficiency on Total Consumption

Estimated BTS Power Consumption vs. Power

Amplifier Efficiency (240W total peak RF Power)

0

500

1000

1500

2000

2500

3000

3500

4000

0% 20% 40% 60% 80% 100%

RF Power Amplifier Efficiency %

DC Power Consumption

Total BTS Power at Busy Hour

OPEX Power (weighted avg)

240 Watt Limit

There are diminishing returns of amplifier efficiency improvements, and utility in reducing the “overheads.”


16

Efficiency metricsFocus on power consumption, not a peak efficiency metric

0

20

40

60

80

100

0 100 200 300 400DC Power Input Watts (the Dependant Variable)

RF Power Output (W

atts)

Digital, Optical & DC/DC

Modeled Remote Radio Head Power characteristics

40%

amp

effic

ienc

y

22% RR

H

efficie

ncy

Low load

efficiency


17

Trends in base station power consumption

Peak Power Consumption under full load

100

1000

10000

2007 2009 2011 2013 2015

Year

DC Power Consumed

GSM Indoor

CDMA Indoor

LTE Indoor

UMTS Indoor

120 Watt Limit

forecasts

GSM

CDMA

WCDMA

All configurations deliver approximately 160 to 180 Watts of RF at top of cabinet for Indoor units, at

RRH output for UMTS.


18

Efficiency Trends

75% efficiency improvement achievable from 2008 to 2015 with current trends

>75% with deployment innovations, e.g.:

� Remote Radio Heads/Tower Mounted Power Amplifiers � ~ 25% reduction

� Powering down GSM carriers with low traffic � another ~ 24 % reduction

� Judicious deployment of low power small cells to serve “hot spots”

OPEX Watts/ kbps

Daily Average Power per Aggregate Downlink Average data Rate (5MHz)

(100µJ/b)

Accelerated Plans

0.01

0.10

1.00

10.00

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

Year of Product Introduction

CDMA

GSM

WCDMA

LTE

60% 60++%45%

EDPD &

Doherty

50%

Digital Doh

Enh. DPD--- 75% Reduction from 2008 to 2015 = 18% YOY.

MCPA-2

GPRS EDGE

Twin-TRX GERAN MC-TRX

TRDU

64QAM RLIC

DORAModCell

4.0

EVDO

3G1X

HSDPA R5

HSDPA R62x2 MIMO

RLIC, QOF

4x2 MIMO

Trend line for 75% reduction from 2008 to 2015


19

Wireless Network Power Efficiency Trends

BTS Power consumption Trends— 12% YOY reduction of canonical BTSs

— 18% YOY improved efficiency (aka 75% in 7 years)

— ~>25% YOY with improved deployment efficiencies

Power efficiency of ALU wireless products have been improving about 18% YOYover many decades

OPEX Watts/ kbps


(100µJ/b)

Accelerated Plans

0.01

0.10

1.00

10.00

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015


CDMA

GSM

WCDMA

LTE 5MHz

LTE 10MHz

60%

N-Way Doh

SOC (BB)

60++%

Class S

impr. SOC

45%

EDPD &

Doherty

50%

Digital Doh

DPD--- 75% Reduction from 2008 to 2015 = 18% YOY.

MCPA-2

GPRS EDGE

Twin-TRX GERAN MC-TRX TRDU

64QAM RLIC

60WC2PAMDORA

40WC2PAM

ModCell

4.0

EVDO

3G1X

HSDPA R5

HSDPA R62x2 MIMO

RLIC, QOF

4x2 MIMO


OPEX Watts/ kbps


(100µJ/b)

Accelerated Plans

0.01

0.10

1.00

10.00

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015


CDMA

GSM

WCDMA

LTE 5MHz

LTE 10MHz

60%

N-Way Doh

SOC (BB)

60++%

Class S

impr. SOC

45%

EDPD &

Doherty

50%

Digital Doh

DPD--- 75% Reduction from 2008 to 2015 = 18% YOY.

MCPA-2

GPRS EDGE

Twin-TRX GERAN MC-TRX TRDU

64QAM RLIC

60WC2PAMDORA

40WC2PAM

ModCell

4.0

EVDO

3G1X

HSDPA R5

HSDPA R62x2 MIMO

RLIC, QOF

4x2 MIMO


1979AMPS

61 Watts/kbps

The longstanding improvement trend dates all the way

back to the beginning, to 1979 and the Chicago trial of

Analog AMPS. That base station consumed 530 Amps at

24VDC for a total of 12.72kWatts of DC power while

generating 16 channels on each of 3 sectors all at 10 Watts

of RF. The DC to RF conversion was: 3x160/12720 = 3.8%.

But 3dB cable losses reduces this to 1.9% to transmitted RF.

Each channel supported 10kbps, so this amounts to a consumption rate of 61 Watts/kbps.

This is a remarkably close fit to the 18% YOY curve fit of the last decade’s data.


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Power consumption trends in wireless networks